The production of isochromans is disclosed in the prior art and certain novel isochromans have been disclosed with an outstanding musk fragrance. Such isochromans especially adapted for perfumery by virtue of their fragrance properties were disclosed in Heeringa and Beets, U.S. Pat. No. 3,360,530, issued on Dec. 26, 1967 as well as U.S. Pat. No. 3,978,090, issued on Aug. 31, 1976 to Sanders and Michael. Furthermore, the production of cyclic nitriles has been shown in the prior art and certain bicyclic nitriles have recently been disclosed with an outstanding musk fragrance. Such bicyclic nitriles especially adapted for perfumery by virtue of their fragrance properties have been disclosed in Kulka, U.S. Pat. No. 3,910,853, issued on Oct. 7, 1975. The reaction route for producing these nitriles is set forth, inter alia in U.S. Pat. No. 3,910,853 at Column 2 and at Column 3 as follows: ##STR6## "in which R is methyl or ethyl." (R can also be hydrogen).
"The resulting 1,1,4,4-tetramethyl-6-alkyl-1,2,3,4-tetranydronaphthalene is chloromethylated with paraformaldehyde and hydrochloric acid in the presence of glacial acetic acid and phosphoric acid to produce 1,1,4,4-tetramethyl-6-alkyl-7-chloromethyl-tetrahydronaphthalene in accordance with the following reaction: ##STR7## The resulting 1,1,4,4-tetramethyl-6-alkyl-7-chloromethyl-tetrahydronapthalene is then reacted with 2-nitropropane and sodium methoxide in methanol solution. An exothermic reaction takes place. After the completion of the reaction, water and benzene are added. The resulting mixture is then separated into an organic part and an aqueous part. The organic part is washed successively with a 5% sodium hydroxide solution followed by two washings with water. The benzene is removed by distillation and the reaction product solidified. The resulting product may be recrystallized from a suitable solvent such as methanol. The reaction which takes place is as follows: ##STR8## The 1,1,4,4-tetramethyl-6-alkyl-7-formyl-tetrahydronaphthlene formed is reacted with hydrolxyamine hydrochloride dissolved in water. The reaction mixture is agitated for a period of about 5 minutes, after which a solution of sodium hydroxide is added. After agitation for about 3 hours, the reaction mixture is cooled by the addition of shaved ice. The reaction mixture is then saturated with carbon dioxide by the gradual addition of solid carbon dioxide. The mixture is permitted to stand for several hours. The reaction which takes place is as follows: ##STR9## The resulting 1,1,4,4-tetramethyl-6-alkyl-7-aldoxime tetrahydronaphthalene is reacted with acetic anhydride. The mixture is agitated and gradually heated over a period of about 15 minutes, to about 123.degree. C. It is then refluxed for 1 hour. The reaction mixture is then permitted to cool to room temperature and a mixture of water and benzene is added. The reaction product in benzene solution is then washed successively 3 times with water, twice with aqueous sodium carbonate solution, once with aqueous sodium bicarbonate solution and finally with water. The solvent is removed by distillation and the product recrystallized by a suitable solvent such as methanol. The reaction which takes place is as follows: ##STR10##
The process for producing isochromans of U.S. Pat. No. 3,978,090 having the structure: ##STR11## "wherein R.sub.1 and R.sub.2 are each (i) separately selected from the group consisting of hydrogen, lower alkoxyl, lower alkyl, and, (ii) taken together, selected from the group consisting of benzo, cyclopentano, cyclohexano, naphtho, monoalkyl cyclopentano, polyalkyl cyclopentano, monoalkyl cyclohexano and polyalkyl cyclohexano, and R.sub.3 and R.sub.4 are the same or different and are selected from the group consisting of hydrogen and lower alkyl comprises the steps of intimately admixing:
A. An alkanol having the structure: ##STR12##
B. An acetal having the structure: ##STR13## (wherein R.sub.5 and R.sub.6 are each 2-propyl);
C. A protonic acid selected from the group consisting of p-toluene sulfonic acid and phosphoric acid; and
D. An azeotroping agent selected from the group consisting of n-hexane, cyclohexane, methyl cyclohexane, benzene and toluene; and simultaneously (i) heating the resulting mixture for a period of time whereby a substantial amount of the isochroman having the above structure is formed while (ii) azeotropically removing water of reaction with the azeotroping agent."
A specific example of one of the reactions of U.S. Pat. No. 3,978,090 is the reaction of the iso-propylalcohol acetal of formaldehyde with 2-(1', 1', 2', 3', 3'-pentamethylindan-5'yl)-propanol-1 which yields 6-oxa-1,1,2,3,3,8-hexamethyl-2,3,5,6,7,8-hexahydro-1H-benz(f)indene as follows: ##STR14## Another example of this process is the formation of 2-oxa-4,5,5,8,8,-pentamethyl-1,2,3,4,5,6,7,8-octahydroanthracene as follows: ##STR15##
Alternative routes are also available for the production of isochromans such as those set forth in U.S. Pat. No. 3,360,530 and one of the most straightforward of these routes is the treatment of a Friedel Crafts reactant with an alkaline oxide under Friedel Crafts conditions to form an aryl alkanol. The aryl alkanol is then isolated and thereafter reacted with formaldehyde to cyclialkylate the alcohol.
The efficiency of the aforesaid multistage processes leaves much to be desired because of yield impairment due to the large amount of working required.
In addition, U.S. Pat. No. 3,532,719 sets forth a process for producing such isochromans, which process at the time of patent application, solved a number of these problems of the processes set forth in U.S. Pat. No. 3,360,530. U.S. Pat. No. 3,532,719 provided a more simplified more economical process for producing isochromans which comprises reacting a Friedel Crafts reactant with alkaline oxide in the presence of aluminum chloride to form an aryl alkanol, partially deactivating the aluminum chloride after formation of the aryl alkanol and cyclialkylating the aryl alkanol with formaldehyde in the presence of the partially deactivated aluminum chloride to form the isochroman. The disadvantage of such procedures for the preparation of isochromans is in the first step wherein the Friedel Crafts reactant is formed (e.g. the bicyclic hydrocarbon) and in the second step wherein chloromethylmethylethers may be involved which have been reported to be health hazards accordingly requiring special precautions when handling. The preparation and use of such chloromethylmethylethers and the use of aluminum chloride complexes give rise to the release of hydrogen chloride vapors and formation of aqueous hydrogen chloride solutions require the use of more expensive glass lined vessels due to the more corrosive mixtures in the reaction.
The question of dealkalytion, transakalytion and reversability in the Friedel Crafts reaction is extensively discussed in "Friedel Crafts and Related Reactions", Volume 1 edited by G. A. Olah, Interscience 1963 at pages 36 and 37 wherein it is stated:
"It has long been known that the action of aluminum chloride is not restricted to the introduction of alkyl groups into aromatics. It can also be used to remove alkyl groups from alkylbenzenes (dealkylation) . . . Therefore it has often been stated that Friedel Crafts alkylations are reversible . . . Hexamethylbenzene heated at 190.degree.-200.degree. with aluminum chloride gives methyl chloride and a mixture of hydrocarbons: pentamethylbenzene, durene, isodurene, trimethylbenzenes, xylenes, and small amounts of benzene and toluene. If a stream of dry hydrogen chloride is passed through the mixture the dealkylation is easier and more complete. When methylbenzenes having 1-4 methyl groups are heated with aluminum chloride, dealkylation and alkylation proceed together so that the product is a mixture of hydrocarbons, some with fewer and some with more alkyl groups than the original alkyl benzene. Thus mesitylene yields xylenes and durenes, as well as smaller amounts of toluene and benzene. Alkyl groups containing two or more carbon atoms are readily transferred from one position to another and from one benzene nucleus to another (intra- and intermolecular isomerization). Polyethylbenzenes react with benzene to give ethylbenzene. Isopropyl and t-butyl groups are still more readily transferred and one alkyl group can displace another."
The Olah publication is not considered to disclose either explicitly or implicitly the reaction of my invention.
Although condensation of ditertiary glycols with benzene is disclosed at Chem. Abs. (1952) 5022(b) (Abstract of Labunskii and Tsukervanik, Doklady, Akad. Nauk S.S.R. 80 369-72), the instant disproportionation reaction is not so disclosed therein. The Chem. Abstract reference states:
"C.sub.6 H.sub.6 concenses with (Me.sub.2 C(OH).sub. 2 only if 2-2.5 moles AlCl.sub.3 are used at 80.degree., yielding 8% 1,1,2-trimethyl-indan and some 50% Me.sub.2 CAc. CH.sub.2 (CMe.sub.2 OH).sub.2 with 1.5 moles AlCl.sub.3 at 50.degree.-70.degree. yields 52.5% 1,1,3,3-tetramethyl-indan and 18% 1,2,3,5,6,7-hexahydro-1,1,3,3,5,5,7,7-octamethyl-indacene, m. 214.degree., while 2,5-dimethyl-2,5-hexanediol similarly gives 57.3% 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene and 1,1,4,4,5,5,8,8-octamethyl-1,2,3,4,5,6,7,8-octahydroanthracene (20%). Reaction with MeCH-(OH)CH.sub.2 C(OH)Me.sub.2 with 1.5 moles AlCl.sub.3 at 50.degree.-60.degree. gave 20% Me.sub.2 CPhCH.sub.2 CH(OH)Me and 25% 1,1,3-trimethyl-indan. Me.sub.2 C(OH)CH.sub.2 COMe with 2 moles AlCl.sub.3 at 20.degree. gave 61% PhCH.sub.2 CHMeCH.sub.2 COMe and a little unknown product, m. 127.degree.. The mechanism is probably analogous to that given for ROH (Byull. Sredneaziat. Gosudarst. Univ. No. 25, 45(1947), with additional possibility of intermediate formation of oxido structures."
In Chem. Abstracts 163,834d, Volume 77, 1972 (Abstract of Badr and Zarif, J. Appl. Chem. Biotechnol. 1972, 22(9), 967-72) rearrangement of bicyclic aromatics using phenol and naphthol is disclosed thusly:
"Isomerization of alkyl naphthalenes by anhydrous sulfonic acids or Friedel-Crafts and Lewis Acid catalysts was studied, where alkyl groups underwent rearrangement during the isomerization. Isomerization of benzylnaphthalenes, in presence of phenol and naphthols, resulted in the alkylation of the solvents, giving benzylphenols, benzyl naphthols and the normal products of isomerization."
Chem. Abstracts 59:3847h (Abstract of Shadmanov (Belinskii Ped. Inst. Tashkent) states that condensation of 2,5-dimethyl-2,5-dichlorohexane (I) with C.sub.6 H.sub.6 gives 1,1,4,4-tetramethyltetrahydronaphthalene (II) and 1,1,4,4,5,5,8,8-octamethyloctahydroanthracene (III). With use of the molar ratio C.sub.6 H.sub.6 --I--AlCl.sub.3 - 45.8:1:0.1 and temp. 76.degree.-80.degree. for 24 hours only II (85%), b.sub.3 98.degree.-100.degree., n.sub.D.sup.20 = 1.5218, d=0.9328 was obtained. Working with temp. 20.degree.-2.degree. for 72 hours only III (60-78%) b. 218.degree.-20.degree. was obtained. ##STR16##
The aforementioned teachings do not however, imply that the disproportionation reaction of the instant invention can take place under the stated conditions.
Preparation of 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene using aluminum chloride as a catalyst is disclosed in Bruson and Kroeger, Volume 62, J. Am. Chem. Soc. January 1940, Pages 36-44 (Title: "Cycli-Alkylation of Aromatic Compounds by the Friedel and Crafts Reaction"). However, the disproportionation reaction of the instant invention is not disclosed by Bruson and Kroeger.